What is the subnet magic number? What is it, really? It makes subnetting quick and easy to figure out in seconds. The result was to make classful networks more manageable and efficient, by creating subnets and reducing the number of host addresses per subnet to what is actually required. This need was met progressively through the conceptions of subnet masks, variable-length subnet masks (VLSM) and classless inter-domain routing (CIDR). That is, to provide a way to limit the number of host addresses per network segment to what is actually needed, regardless of the network class. For these and other reasons, there was a need to improve the efficiency of IP addressing. Why subnetting? Thanks to subnetting, networks no longer need to be divided solely on the basis of class because it became very apparent that class A and B networks were simply too large - 254 (2^8 - 2) hosts on one network segment is manageable, but 65534 (2^16 - 2) hosts or more on a single network segment is difficult to manage. This divides a network into smaller subnets. In other words, subnetting involves starting with a default (A, B, or C) network, “stealing” bits from the host portion, and adding them to the network side. The practice of dividing a network into two or more networks is called subnetting.
If you can find the subnet number and broadcast address, you can easily find the range of valid addresses in the subnet.A subnetwork or subnet is a logical subdivision of an IP network. To get the correct answers faster on the exam, you might want to avoid all the conversions and binary math. Using the binary math required to find the subnet number and broadcast address really does help you understand subnetting to some degree. You can derive the subnet number and broadcast addresses without converting to and from binary or performing Boolean math.
#How to find subnet magic number software#
Using the Simulation Software for the Hands-on Exercises.Answers to the “Do I Know This Already?” Quizzes and Q&A Questions.Solutions to Scenario 2, Part A: Planning.Solutions to Scenario 1, Part A: Planning.A Partially-Meshed Network with Some Fully-Meshed Parts.A Partially-Meshed Network with One IP Subnet Per VC.A Fully-Meshed Network with One IP Subnet.Frame Relay Layer 3 Addressing: Hybrid Approach.Frame Relay Layer 3 Addressing: One Subnet Per VC.Frame Relay Layer 3 Addressing: One Subnet Containing All Frame Relay DTEs.Network Layer Concerns with Frame Relay.DDR Step 4: Determining When the Connection Is Terminated.DDR Step 2: Determining the Subset of the Packets That Trigger the Dialing Process.DDR Step 1: Routing Packets Out the Interface to Be Dialed.ISDN PRI Function Groups and Reference Points.ISDN BRI Function Groups and Reference Points.Data-Link Protocols for Point-to-Point Leased Lines.Physical Components of Point-to-Point Leased Lines.Internet Control Message Protocol (ICMP).Overloading NAT with Port Address Translation (PAT).Scaling the IP Address Space for the Internet.Classless and Classful Routing Protocols.Classless Routing Protocols and Classless Routing.
#How to find subnet magic number how to#
How to Use These Books to Prepare for the CCNA Exam.Cross-Reference Between Exam Topics and Book Parts.Cisco’s Motivation: Certifying Partners.